Management of monogenic diabetes in pregnancy: A narrative review

Table 1 Classification of maturity-onset diabetes of the young

MODY type	MODY sub-type	Genes affected	Characteristics features
HNF4A-MODY	MODY 1	HNF4A	Young-onset hyperglycemia, pancreatic beta cell dysfunction, sensitive to sulfonylurea treatment, macrosomia, transient neonatal hyperinsulinism
GCK-MODY	MODY 2	GCK	Mild fasting hyperglycemia, stable glucose levels, lack of complications
HNF1A-MODY	MODY 3	TCF1	Young-onset hyperglycemia, sensitive to sulfonylurea treatment, renal cysts, genital tract anamolies
PDX1-MODY	MODY 4	PDX1	Young-onset hyperglycemia, pancreatic agenesis, hypopituitarism, growth retardation
HNF1B-MODY	MODY 5	HNF1B	Young-onset hyperglycemia, renal abnormalities, genital tract malformations, gout
NEUROD1-MODY	MODY 6	NEUROD1	Young-onset hyperglycemia, retinal dystrophy, cerebellar ataxia, epilepsy, intellectual disability, sensorineural hearing loss
KLF11-MODY	MODY 7	KLF11	Young-onset hyperglycemia, hepatic steatosis
CEL-MODY	MODY 8	CEL	Neonatal diabetes, pancreatic atrophy, exocrine pancreatic insufficiency, transient neonatal hyperinsulinism
PAX4-MODY	MODY 9	PAX4	Adult onset diabetes, multisystem disorder, mutation inhibits beta-cell proliferation, ketosis prone
INS-MODY	MODY 10	INS	Neonatal diabetes, insulin gene mutation, requires lifelong insulin treatment
BLK-MODY	MODY 11	BLK	Young-onset hyperglycemia, reduced beta-cell mass
ABCC8-MODY	MODY 12	ABCC8	Neonatal diabetes, potassium channel gene mutation, responsive to high-dose sulfonylurea
KCNJ11-MODY	MODY 13	KCNJ11	Neonatal diabetes, potassium channel gene mutation, responsive to high-dose sulfonylurea
APPL1-MODY	MODY 14	APPL1	Young-onset diabetes and decreased glucose mediated insulin release, dysmorphic features and developmental delay in animal models

HNF4A: Hepatocyte nuclear factor 4 alpha; GCK: Glucokinase; TCF1: Transcription factor 1 (also known as HNF1A); PDX1: Pancreatic and Duodenal Homeobox 1; HNF1B: Hepatocyte nuclear factor 1 beta (also known as TCF2); NEUROD1: Neurogenic differentiation 1; KLF11: Krüppel-like factor 11; CEL: Carboxyl ester lipase; PAX4: Paired box 4; BLC2L1: B-cell CLL/lymphoma 2 like 1; INS: Insulin; BLK: B-lymphocyte kinase; APPL1: Adaptor protein, phosphotyrosine interaction, PH domain, and leucine zipper containing 1; ABCC8: ATP-binding cassette subfamily c member 8 (also known as SUR1); KCNJ11: potassium voltage-gated channel subfamily J member 11 (also known as Kir6.2).

Table 2 Complications of glucokinase maturity-onset diabetes of the young in pregnancy

Outcome feature	Percentage	Ref.
Miscarriage	15%-33%	[9,27]
Preterm birth	12%	[27]
Low birth weight	6%	[28]
Macrosomia	3%	[23]
Neonatal hypoglycemia	10%	[23]
Congenital malformations	2%-3%	[23]